Search PubMed⌕ Search

Biomedical subjects

Michael J Reardon

Publications and source records attributed to Michael J Reardon.

27 records · Page 2Linked to original sources
PubMed2003

Endoscopic vein harvesting in cardiac surgery.

PURPOSE OF REVIEW: Endoscopic vein harvesting (EVH) is a relatively new technique, developed to help minimize morbidities associated with traditional harvesting techniques. Wound dehiscence, recurrent cellulitis, hematomas, neuropathies, and impaired mobility are often experienced by patients who have undergone open harvest techniques. RECENT FINDINGS: Use of this developing technique has been hindered due to the skill required to perform this task and time constraints that are often encountered in the operating room. SUMMARY: However, an adequate vein segment can be obtained in a timely fashion, and harvest site infections are reduced when this method is employed. Results thus far have revealed a decreased infection rate, fewer observed morbidities, and overall patient satisfaction.

Cardiac Surgical Procedures↗
PubMed2003

A combined modality approach to recurrent cardiac sarcoma resulting in a prolonged remission: a case report.

We report a case of cardiac fibrosarcoma that was treated with cardiac tumor resection, chemotherapy, cardiac explantation, tumor repeat resection, and autotransplantation followed by external beam irradiation. The patient was able to achieve clinical remission and remained disease free > 2 years after the initial diagnosis. This case report demonstrates that a sustained remission from cardiac sarcoma is possible with an aggressive combined modality approach.

Adult↗
PubMed2002

Relation of tissue Doppler-derived myocardial velocities to serum levels and myocardial gene expression of tumor necrosis factor-alpha and inducible nitric oxide synthase in patients with ischemic cardiomyopathy having coronary artery bypass grafting.

We evaluated the relation of segmental and annular tissue Doppler (TD) velocities to serum levels and myocardial gene expression of tumor necrosis factor-alpha (TNF-alpha) and inducible nitric oxide (NOS2) in humans. Seven patients with coronary artery disease underwent echocardiographic examination including TD imaging, along with transmural endomyocardial biopsies (2 biopsies per patient for a total of 14 specimens) at the time of bypass surgery. The specimens were analyzed for the number of mRNA copies of TNF-alpha and NOS2. In addition, serum levels of TNF-alpha and nitrite were determined before and after surgery. Normal segments (n = 7) had fewer numbers of mRNA copies of both TNF-alpha (54.6 vs 6.5, p = 0.002) and NOS2 (3,093 +/- 486 vs 661 +/- 259, p <0.001) than dysfunctional segments (n = 7). Peak systolic velocity (Sm) (13.3 +/- 1.4 vs 4.9 +/- 1.6 cm/s, p = 0.002) and early diastolic velocity (Em) (16.5 +/- 2.7 vs 8.8 +/- 1.3 cm/s, p = 0.02) were significantly higher in normal segments. A significant correlation was present among Em, Sm, and the number of mRNA copies of TNF-alpha and NOS2 at baseline and during infusion of dobutamine (r range -0.72 to -0.92, p <0.01 for all). Likewise, significant relations were present between the changes in serum cytokine levels and changes in the mitral annulus diastolic velocity, E/Ea ratio, and end-diastolic wall stress (r range 0.75 to 0.88, p </=0.05 for all). In conclusion, Sm and Em are strongly dependent on the regional levels of cytokine gene expression, which are known to have negative inotropic and lusitropic effects when overexpressed.

Aged↗
PubMed2002

Microvascular structural correlates of myocardial contrast echocardiography in patients with coronary artery disease and left ventricular dysfunction: implications for the assessment of myocardial hibernation.

BACKGROUND: Myocardial contrast echocardiography (MCE) has been used to evaluate myocardial viability. There are no data, however, on the pathological determinants of myocardial perfusion by MCE in humans and the implications of such determinants. METHODS AND RESULTS: MCE was performed in 20 patients with coronary artery disease and ventricular dysfunction within 24 hours before myocardial biopsy at surgery using a continuous Optison infusion (12 to 16 cc/h), with intermittent pulse inversion harmonics and incremental triggering. Peak myocardial contrast intensity (MCI) and the rate of increase in MCI (beta) were quantitated. Thirty-six transmural myocardial biopsies (2 per patient) were obtained by transesophageal echocardiography. Total microvascular (<100 microm) density, capillary density and area, arteriolar and venular density, and percent collagen content were quantitated with immunohistochemistry. Peak MCI correlated with microvascular density (r=0.59, P<0.001) and capillary area (r=0.64, P<0.001) and inversely correlated with percent collagen content (r=-0.45, P=<0.01). The best relation was observed when the ratio of peak MCI in the 2 biopsied segments in each patient was compared with the ratio of microvascular density and capillary area (r=0.84 and 0.87, respectively; P<0.001). A significant overlap in microvascular density was seen between segments with and without recovery of function. The new MCE indices of blood velocity (beta) and flow (peak MCIxbeta) better identified recovery of function compared with microvascular density and the sole use of peak MCI. CONCLUSIONS: Microvascular integrity is a significant determinant of maximal MCI in humans. MCE indices of blood velocity and flow are important parameters that predict recovery of function after revascularization.

Aged↗
PubMed2002

Increased myocardial gene expression of tumor necrosis factor-alpha and nitric oxide synthase-2: a potential mechanism for depressed myocardial function in hibernating myocardium in humans.

BACKGROUND: Whether cardioinhibitory cytokines are elevated in regions of hibernating myocardium and account in part for the depression in resting function is currently not known. Methods and Results- Thirteen patients with stable ischemic ventricular dysfunction scheduled for bypass surgery underwent preoperative dobutamine echocardiography (DE) and intraoperative myocardial biopsies. The numbers of copies of mRNA for the negatively inotropic cytokines tumor necrosis factor-alpha (TNF-alpha) and inducible nitric oxide synthase (NOS2) were quantified by reverse transcription-polymerase chain reaction. In normal segments, myocardial TNF-alpha was barely detectable (1.2+/-0.4 copies per 10(6) copies of beta-actin). A 13.7-fold increase in myocardial TNF-alpha was observed in dysfunctional segments with a biphasic response to DE (contractile reserve and ischemia) and was highest (45.5-fold) in segments with ischemia and without contractile reserve (P<0.001). A similar graded increase was seen for NOS2. Cytokine results were also similar if analysis was performed using recovery of function at 3 months as the index of viability. The change in serum TNF-alpha and nitrite levels from baseline to 3 months after surgery correlated inversely with both the change in ejection fraction and the number of DE viable segments (r=-0.92 to -0.93; P<0.001). CONCLUSIONS: TNF-alpha and NOS2 gene expression is regionally upregulated in hibernating myocardium to a level intermediate between that of normal regions and ischemic regions without contractile reserve. This, along with a decline in serum cytokine levels after revascularization proportional to the extent of myocardial viability, suggests a contributing role for cardioinhibitory cytokines in the observed depression of function seen in hibernating myocardium.

Female↗
PubMed2002

Evidence for an active inflammatory process in the hibernating human myocardium.

Myocardial hibernation refers to a state of prolonged impairment of left ventricular function in the presence of coronary artery disease, which may be reversed by revascularization. In this study we present evidence for a local inflammatory reaction in hibernating myocardial segments from patients undergoing coronary revascularization. We obtained transmural myocardial biopsies guided by transesophageal echocardiography from patients with ischemic ventricular dysfunction undergoing bypass surgery. Among the 28 biopsied segments included in the study, 23 showed evidence of systolic dysfunction. The majority of dysfunctional segments (85.7%) were viable ((201)Tl uptake >/= 60%). The samples were stained with markers for mast cells, mature resident macrophages, and the monoclonal antibody Mac387 that labels newly recruited myeloid cells. Dysfunctional segments showed more extensive fibrosis and higher macrophage density than normal segments. Among the 23 dysfunctional segments, 12 recovered function as assessed with echocardiograms 3 months after revascularization. Segments with postoperative functional recovery had comparable macrophage and mast cell density with those showing persistent dysfunction. However, biopsied segments that subsequently recovered function contained significantly higher numbers of newly recruited Mac387-positive leukocytes (18.7 +/- 3.1 cells/mm(2), n = 12 versus 8.6 +/- 0.9 cells/mm(2), n = 11; P = 0.009). In addition, monocyte chemotactic protein-1, a potent mononuclear cell chemoattractant, was predominantly expressed in segments with recovery of function. Myocardial hibernation is associated with an inflammatory response leading to active leukocyte recruitment. Dysfunctional myocardial segments that show an active inflammatory reaction have a greater potential for recovery of function after revascularization. We postulate that revascularization may promote resolution of the ongoing inflammation, preventing further tissue injury and fibrosis.

Aged↗
PubMed2002

Outcomes in single versus bilateral internal thoracic artery grafting in coronary artery bypass surgery.

The authors analyzed the early outcomes in two groups of patients undergoing coronary artery bypass grafting (CABG) with single versus bilateral internal thoracic arteries (ITA) in their institution. One thousand sixty-nine patients underwent CABG with single or bilateral ITAs from 1990 to 2000. Of these patients, 911 (85.2%) had single ITA and 158 had bilateral ITA (14.8%). The incidence of tobacco abuse was 40.3% in the single ITA group and 56.7% in the double ITA group (P = 0.0001). The incidence of perioperative myocardial infarction, renal failure, reoperation for bleeding, stroke, or operative mortality did not differ in the two groups. There was a 4.4% incidence of mediastinitis in the bilateral ITA group versus 2.2% in the single ITA group (P = 0.0602). Early outcomes after bilateral ITA grafting for CABG are similar to single ITA grafting. Careful judgment should be exercised in selecting patients for bilateral ITA grafting, particularly if the patient smokes.

Aged↗
PubMed2002

Autotransplantation of the heart for primary cardiac malignancy: development and surgical technique.

Primary cardiac malignancy presents an unusual and difficult surgical challenge. Malignant tumors of the left atrium have proved problematic due to their posterior location and difficulty of surgical exposure. The technique of cardiac explantation, ex vivo resection and cardiac reconstruction, and reimplantation--the cardiac autotransplantation procedure--was developed to solve this anatomic problem. Herein, we discuss the development of this approach and describe the surgical technique.

Cardiopulmonary Bypass↗